The terminology catalytic reactor is generally used to describe a vessel comprising a catalyst. Catalytic reactors are used to catalyze chemical reactions in fluid streams passing through the reactor. Catalyst reactors generally comprise catalytic structures containing fluid flow paths that enable contact between the fluid streams and catalytically active components of the catalytic structure. The catalytic structure of a modular catalytic reactor is typically composed of one or more catalytic layers with each layer comprising a large number of modularized sections. Each modularized section further comprises a metal support framework which holds a large number of catalyst bodies in place wherein sealing or packing materials between the catalyst bodies is used if necessary for proper flow distribution of fluid streams passing through the catalyst bodies. The catalyst bodies contain the catalytic composition and display a physical structure that delineates flow channels or passageways for fluid flow through the catalyst bodies.
Catalyst bodies within modularized sections of catalytic layers in a catalytic reactor may need replacement for a variety of reasons. Catalyst bodies with more desirable properties may become available. Moreover, the catalytic function within catalyst bodies can degrade due to exposure to operating conditions which include poisoning or masking by species that bind to or obstruct the efficient contact of fluid components with catalytic sites. Catalyst bodies can additionally become plugged as a result of being exposed to fluids containing high contents of particulate matter. Plugging by particulate matter degrades the catalytic function of catalyst bodies by precluding the efficient flow of fluids through the bodies for reaction with the catalytic material therein.
Spent catalyst bodies within modularized sections of catalytic layers in a reactor are replaced in order to maintain or improve the overall catalytic efficiency of the reactor. Replacement of catalyst bodies by removal of modularized sections of a catalytic reactor is an expensive and time consuming process. The replacement generally requires cutting open one or more welded catalyst loading doors, removing modularized catalyst sections that contain spent or damaged catalyst bodies from the catalytic reactor and inserting replacement modularized sections. Removing modularized sections from the reactor is time consuming and costly since the removal process requires specialized rigging. Typical modularized sections may have dimensions of 38 inches×63 inches×75 inches and a weight up to several thousand pounds. In existing procedures, once the modularized sections are removed from the catalytic reactor, they must be transported to an onsite or offsite location for either storage, disposal, recycling, cleaning, or replacement of the spent catalyst bodies, or for rejuvenation of catalytic functionality using, for example, a regeneration process. The transportation of the modularized sections increases the cost and time associated with replacing catalyst bodies within a reactor.
In view of the disadvantages of existing procedures, it would be desirable to provide methods for replacing catalyst bodies within modularized sections of a catalytic reactor that provide increased cost and time efficiencies over present replacement methods.